I've read that a (major) difference between Catholic and Lutheran theology is the doctrine of transubstantiation. At first glance, the Lutheran and Catholic approach to Holy Communion seem to be quite similar. Could you explain?

The Catholic church believes that only priests ordained by bishops in communion with the Pope or in the apostolic succession of the Eastern church have the power to consecrate the bread and wine so that they become body and blood of Christ and that nothing of the substance of the bread and wine remains, only body and blood. They also believe that the elements remain Christ’s body and blood even after the mass is over. The elements can be reserved in a special place. The elements can be bowed to and prayed to. They believe the mass is a sacrifice. They also curse everyone who does not accept this view.

We believe that, together with the bread and wine, Christ’s body and blood are truly present, however, this does not depend on papal ordination but on Christ’s institution. We do not accept the adoration (worship) of the host, nor do we believe that a sacrifice takes place. We stick just to what the Words of Institution say.